An Efficient Cell Selection Approach in 4G Networks

The cell selection mechanism that provides services to each mobile station is referred to as cell selection. For maximizing the current and future of cellular networks, it is necessary to optimize the process. The OFDMA-based systems are LTE-Advanced and IEEE 802.16m for satisfying the mobile station minimum demand by having one or more base station simultaneously. The problem is considered as the optimization problem and defines the problem as it is not considered as NP-hard and also not possible for approximation with a reasonable factor. The assumption is that the maximum required bandwidth of a single mobile station is defined as the r-fraction of the capacity of the base station. For cell selection, this paper consists of two algorithms. The first algorithm defines the creation of a (1-r) approximate solution, this is applicable when the coverage of the mobile station is done by one or more base station simultaneously. The second algorithm defines the creation of an approximate solution (1-r /2-r) when the coverage of each mobile station is covered by a maximum one base station. A simulation research that describes the benefit of using our algorithms that have limited and high-loaded power for the future of 4G networks completes the overall study. The performance and capacity are better than the existing algorithms.

Performance Optimal for Deploying Relays in Urban Micro Cells on LTE-Advanced Technology

Cooperative Relay is a promising enhancement to modern radio technologies which has been considered in LTE-Advanced and IEEE 802.16m technologies. Cooperative Relay is one of the technologies that used to improve coverage in downlink mobile network. The work is done by designing numerous environments for LTE-Advanced networks involving relays, whereby using vertical distributions of relays for both AAF & DAF techniques as well as comparison between the performances optimal of both techniques on urban micro cell for LTE-Advanced Technologies, Insertion the channel model from WINNER project. The performances optimal of non-Cooperative Relay and Cooperative Relay are evaluated in terms of Symbol Error Rate (SER) and Signal-to Noise-Ratio (SNR). The simulation results show that relay technologies can effectively improve system performance. On the other hand, 10-Relay in vertical distributions clearly shows outperforms on other environments and, when the relay put near, middle and far from Evolved Node B (eNB), the result shows at SER of 10-3 the system that employs AAF technique outperforms on the system that employs DAF technique in LTE-A system by about 6.5 dB, 2.5 dB and 2 dB sequent.

Pemodelan Handoff Latency pada Jaringan WiMAX dengan PRISM

Untuk mengetahui performa HHO pada standar protokol WiMAX IEEE 802.16m dilakukan pemodelan dan evaluasi berdasarkan proses handover pada standar protokol tersebut. Analisis simulasi tidak dapat menunjukkan penyebab kesalahan atau error skema handover IEEE 802.16m tersebut. Dalam penelitian ini, sistem handover dimodelkan dengan Continuous-Time Markov Chain. Untuk membangun model rantai Markov sistem handover mengikuti langkah-langkah sebagai berikut: Mereprensentasikan state space berdasarkan asumsi-asumsi pada sistem handover pada jaringan WiMAX, memberikan penomoran pada semua transisi yang mungkin muncul pada semua state, menggenerasikan laju transisi matriks. Kemudian model yang dibentuk dituangkan pada tool PRISM. Evaluasi yang dilakukan terhadap model CTMC yang dibangun menunjukkan bahwa 94 persen dari MS yang melakukan scanning sukses melakukan handover. Handoff latency tidak menjamin kesuksesan dari semua proses handover yang terjadi.